1. Field of the Invention
This invention relates to an apparatus for producing helically coiled coupling elements to be affixed to slide fastener stringer tape and more particularly to an apparatus incorporating stamping means for continuously providing a coupling head portion, a turn portion, a stitching groove and the like at predetermined intervals along the length of a plastic filament prior to winding thereof on a mandrel.
2. Prior Art
Known stamping or forming tools are either of a rotary design or a punch type, but the former is preferred for high speed and accuracy of performance. Efforts have been made to explore means for stamping a filamentary wire material during a course of travel up to the point of winding on a mandrel. In order to effect this stamping without causing twists or wraps in the filament, it is imperative that the stamping means be installed as close to the mandrel as possible. This need coupled with the necessity of enabling the stamping means to rotate on its own axis simultaneously as it makes an orbital movement, poses a great difficulty in the designing, building and operation of such stamping apparatus.